Please disregard this patch.
It contains a bug: function names are copied to the destination buffer first,
and only after that the buffer overrun check is performed, which effectively
means that in the pessimistic scenario the buffer overflow happens first,
and then it is detected. Should be the other way round.
I will post a corrected version soon.
AP
W dniu 09.07.2014 12:24, Andrzej Pietrasiewicz pisze:
When gadgets are composed with configfs the user must know what are the
available function names. The names are parts of usb_f_*.ko
modules' aliases. If a function is compiled as a module, the information
can be found in modules.alias file. But if a function is compiled-in,
there is no way to know the function's name.
This patch adds a sysfs attribute in libcomposite's sys directory to
show functions which are already registered. Functions which are
compiled-in will be in this list as well.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
---
drivers/usb/gadget/configfs.c | 24 ++++++++++++++++++++++++
drivers/usb/gadget/functions.c | 19 +++++++++++++++++++
drivers/usb/gadget/u_f.h | 2 ++
3 files changed, 45 insertions(+)
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index bcc2a62..352571b 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -1553,13 +1553,36 @@ void unregister_gadget_item(struct config_item *item)
}
EXPORT_SYMBOL_GPL(unregister_gadget_item);
+static ssize_t sysfs_func_list_show(struct module_attribute *ma,
+ struct module_kobject *ko, char *buf)
+{
+ return usb_function_list_functions(buf, PAGE_SIZE);
+}
+
+static struct module_attribute sysfs_func_list = {
+ .attr = {
+ .name = "func_list",
+ .mode = S_IRUGO,
+ },
+ .show = sysfs_func_list_show,
+};
+
static int __init gadget_cfs_init(void)
{
int ret;
config_group_init(&gadget_subsys.su_group);
+ ret = sysfs_create_file(&THIS_MODULE->mkobj.kobj,
+ &sysfs_func_list.attr);
+ if (ret)
+ return ret;
+
ret = configfs_register_subsystem(&gadget_subsys);
+ if (ret)
+ sysfs_remove_file(&THIS_MODULE->mkobj.kobj,
+ &sysfs_func_list.attr);
+
return ret;
}
module_init(gadget_cfs_init);
@@ -1567,5 +1590,6 @@ module_init(gadget_cfs_init);
static void __exit gadget_cfs_exit(void)
{
configfs_unregister_subsystem(&gadget_subsys);
+ sysfs_remove_file(&THIS_MODULE->mkobj.kobj, &sysfs_func_list.attr);
}
module_exit(gadget_cfs_exit);
diff --git a/drivers/usb/gadget/functions.c b/drivers/usb/gadget/functions.c
index b13f839..46b2f60 100644
--- a/drivers/usb/gadget/functions.c
+++ b/drivers/usb/gadget/functions.c
@@ -114,3 +114,22 @@ void usb_function_unregister(struct usb_function_driver *fd)
mutex_unlock(&func_lock);
}
EXPORT_SYMBOL_GPL(usb_function_unregister);
+
+size_t usb_function_list_functions(char *buf, size_t len)
+{
+ struct usb_function_driver *fd;
+ char *_buf = buf;
+
+ mutex_lock(&func_lock);
+ list_for_each_entry(fd, &func_list, list) {
+ sprintf(_buf, "%s\n", fd->name);
+ _buf += strlen(fd->name) + 1;
+ if (_buf - buf > len) {
+ mutex_unlock(&func_lock);
+ return -ENOMEM;
+ }
+ }
+ mutex_unlock(&func_lock);
+
+ return _buf - buf;
+}
diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
index 1d5f0eb..f1a8dff 100644
--- a/drivers/usb/gadget/u_f.h
+++ b/drivers/usb/gadget/u_f.h
@@ -47,6 +47,8 @@ struct usb_request;
struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len);
+size_t usb_function_list_functions(char *buf, size_t len);
+
#endif /* __U_F_H__ */
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